Recording-thermometer



(No Model.)

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D. DRAPER. EEGOEDING THERMOMETER.

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' D. DRAPER.

RECORDING THERMOMETER.

No. 380,872. Patented-Apr. 10, 1888..

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UNrTED STATESg PATENT Crimen.

DANIEL DRAPER, OF HASTINGS-UPON-HUDSON, NEW YORK.

RECORDING-THERMOMETER.

SPECIFICATION forming part of Letters Patent No. 380,872, dated April10, 1888.

Application filed November i0, 1887. Serial No. 254,743. (No model.)

To all whom it may concern.-

Be it known that I, DANIEL Daarna, a citizen of the United States,residing at Hastingsupon-Hudson,in the county of Westchester, in theState of New York, have invented certain new and useful Improvements inRecording- Thermometers, of which the following is a specification.

The invention relates to the class of apparatus employed for giving acontinuous record of the variations in temperature occurring at anygiven point.

The object of the invention is to provide simple and convenient meansfor giving a permanent record, which will be exposed to view at alltimes during the period covered by the record-card, and to provide meansfor automatically giving an alarm in case the temperature rises or fallsbeyond predetermined limits.

The apparatus is preferably constructed in substantially the followingmanner: Upon an arbor of a suitable clock-train there is placed arecord-chart properly divided into sections corresponding to days andhours, and by concentric circles into degrees for indicatingtemperature. A recording-pen, which is moved by thermostatic strips,rests upon the surface of this chart and moves toward and from itscenter as the temperature increases or decreases. There are provided twothermostatic strips placed at one side of the arm and constructed tobend in opposite directions under given variations in temperature. Thinwires or threads connect the ends of these arms with two cranks uponthearbor which carries the recording-arm, and they combine to move thesame in the same direction. For this purpose the points of attachmentare upon opposite sides of the arbor. By placing them both upon the sameside of the arbor any jar to which the instrument may be subjected willnot have the effect of moving the recording-arm, for the tendency of onethermostatic strip to move in one direction will be counteracted by thatof the other to move in the same direction, and thus the two forces willbe neutralized with regard to the recording-arm. The chart andrecording-arm are protected by a glass case capable of being openedconveniently for the purpose of removing the chart and replacing it, andupon this cover there is fastened a metallic arm which carries twocontact-points extending into the path of the recording-arm. Thesepoints are adjustable toward and from the center of the chart, and theplate carrying them is preferably curved to correspond to the arcdescribed by the contact-arm, so that the contact-points may easily beadjusted opposite any required degrees of temperature as marked upon thechart. The recording-arm is preferably connected `through the frame ofthe machine, while the contact-points, carried upon the curved plateupon the glass cover, are also provided with a bindingpost, whereby theymay be connected with an electric conductor.

In the accompanying drawings, Figure l is a front view of the apparatus.Fig. 2 is a side View, partly in section. Fig. 3 is a horizontalsection, and Fig. 4 is a plan, of the support for the registering-arm.

Referring to the figures, A represents a frame, preferably of cast-iron,for supporting the various parts. This frame is included in a box, B. Asuitable clock mechanism, B', is also contained in the boX B. Thismechanism is of any convenient character, -preferably an eight-daymovement. Upon the hour-hand b of this clock-train there is carried aplate, C, and at the center of the plate there is a post, c, upon whichthere screws a nut, b. Aflat pin, c', projects from the plate a shortdistance one side of the center. A chart, C', slips over the post c, andthe pin c passes through the chart, thus preventing it from turning.Suitable clamps, c, c3, of, and ci", at the edges of the plate hold thechart in position.

Curved radial lines d d divide the chart into divisions representing thedays of the week, and intermediate lines, d d', divide it into hours.These radial lines are curved to correspond to the arc described by therecordingpoint f, carried upon the end of the recordingarm F. Concentriclines e e divide the chart into other divisions serving to indicatedifferent degrees of temperature. The recordingarm F is more or lessresilient and presses the` recording-point lightly against the surfaceof the chart. It is carricdupon the arbor g, supported in a suitableframe or yoke, G, at the base of the instrument. This arbor is providedwith two levers, H and H2, having IOO curved widened faces. These facesare grooved to receive thin wires or cords 7a and h2, rcspectively. IThewire h is fastened at one end to the end of the thermostatic strip K,and the end of the wire h2 is fastened to the end of a thermostaticstrip, K2. rlhe ends of the two strips are so located as to lie inplanes parallel with the points of attachment of the wires to the curvedlevers. The other ends of the thermostatic strips are secured totheframe A. The strips are reversed with reference to each other, so thatany change of temperature will tend to bend one-strip toward the arbor gand the other strip away from the arbor, so that the two strips combineto move the arbor, and thus the recording-arm. Any jar which is given tothe machine will be absorbed by the two arms, so that no resultanteffect will be manifest upon the recording-arm. The arm F is preferablyloosely mounted upon the arbor g,- but it is provided with an extension,f', passing between two adjustable set-screws, f2 and f, turning throughlugs in a bracket, f, which is rigidly attached to the arbor, and bymeans of these screws the position of the recording-point with referenceto the chart and the thermostatic strips may be very nicely adjusted.The levers H and H2 are preferably also adjustable upon the arbor 0,being held in position by the set-screws lr and It".

For the purpose of giving an alarm in case the temperature exceeds orfalls below any predetermined limits there is attached to the glassfront plate, M, with which the case is closed, a curved plate, a. Thisis fastened by studs passing` through suitable holes formed in the glassand cushioned by washers n and a?. The plate a is curved to correspondwith the are described by the recording-point, and it is provided with alongitudinal slot,m,th rough which there extend two limiting-stops,p'andp2. These are bound in any required position by the nuts p, and theyarerespectively provided with contact-pins t and t2, which are preferablyof platinum. Platinum points may be also formed upon the portion oftherecording-arm F which is opposite the pins, if desired. By adjusting thepins above the points on the chart which indicate any desiredlimits oftemperature the alarm will be sounded when either of these limits isreached. The

binding-post P is fastened to one end of the curved plate a, and thesecond binding-post,

I, is fastened to some portion of the frame or case of the instrument,and these two binding-posts constitute the terminals of any suitablealarm-circuit. The connection from the binding-post P'l to the arm Fwill be through the frame of the machine, the arbor g, also the wires 7Land h2, (in case metallic wires are employcd,) and thus with therecordingarm F. It will be seen that as the alarmplate a is fastened tothe glass plate it will be swung out of the way of the recording-armwhen the door is open to replace the chart. Moreover, when the door isclosed the points cannot be reached, so that unwarranted access to thecontact-points will be prevented.

I claim as my inventionl. In a recording-thermometer, the combination,with a clock-movement and a chart carried thereby, of thermostaticstrips, a rccording-lever actuated thereby, a plate extending over thechart,and insulated contact-points carried upon said plate andadjustable by reference tothe chart to any desired points thereon, saidpoints constituting one terminal of an electric circuit, saidrecording-arm constituting the other terminal.

2. In a recordiiig-thermometer, the combi nation, with therecording-arm, the revolving chart, and the thermostatie strips formoving the arm with reference tothe chart,oftheplate placed in front ofsaid chart and carrying limiting contact-stops adjustable to any desiredpoints in the divisions on the chart, said stops being designed toconstitute the terminals of an electric circuit, substantially asdescribed.

3. In a recording-thermometer, the combination, with the recording-arm,of the chart, the limiting-stops adjustable with reference to thedivisions upon said chart, a support for said stops, the plate ofinsulating material carrying the support in front ofthe chart, andthebindingpost attached to said support and extending through said plate,whereby electrical connection may be made with the supportentside of theplate, substantially as described.

ln testimony whereof I have hereunto subscribed my name this 9th day ofNovember, A. D. 1887.

DANIEL DRAPER.

Witnesses:

J ENNIE P. AsHLEY, CHARLEs A. TERRY.

ICO

